Postgresql 中文操作指南
53.6. pg_attrdef #
pg_attrdef 目录存储列默认值。列的主要信息存储在 pg_attribute 中。只有已明确设置默认值列才会有相应条目。
The catalog pg_attrdef stores column default values. The main information about columns is stored in pg_attribute. Only columns for which a default value has been explicitly set will have an entry here.
Table 53.6. pg_attrdef Columns
Table 53.6. pg_attrdef Columns
Column Type Description |
oid oid Row identifier |
adrelid oid (references pg_class.oid) The table this column belongs to |
adnum int2 (references pg_attribute.attnum) The number of the column |
adbin pg_node_tree The column default value, in nodeToString() representation. Use pg_get_expr(adbin, adrelid) to convert it to an SQL expression. |